Hi Chuck, thanks for your extensive comments about the JVM options..
n828cl wrote: > >>-Xms10240m -Xmx10240m > > That's a very large heap; shouldn't hurt as long as you have enough RAM to > support it all without paging. (But see below for use with compressed > OOPs.) > This shouldn't be a problem, the system has 16 GB RAM, almost all of it dedicated to Tomcat. n828cl wrote: > >> Tomcat's CPU usage seems significantly lower than before >> (it's average seems about 10% now - which was 30-40% before) > > There are some improvements in the JDK/JRE 6 JIT and synchronization > handling, but probably not enough to account for that large a difference. > Well, I don't know where exactly it's coming from, but after a full day very closely monitoring the system, it turns out to be the truth. Which is not a bad thing, of course :) n828cl wrote: > >> I also added the -XX:+UseCompressedOops JVM option > > Be careful with that; it can impact CPU usage, since the compressed OOPs > have to be expanded into actual pointers every time they're used, and > pointers compressed when stored in a field. Works best with heap sizes > less than 4 GB, which avoids the decoding/encoding. For a real > explanation of compressed OOPs, look here: > http://wikis.sun.com/display/HotSpotInternals/CompressedOops > I already found that article myself. Since CPU usage is as low as it is now, I have decided to give it a try. Anyway, thanks again! -- View this message in context: http://old.nabble.com/Tomcat-100--CPU-usage-after-moving-from-Java-5-to-6-tp27305110p27324793.html Sent from the Tomcat - User mailing list archive at Nabble.com. --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
